Belt-tensioning device



May 6, 1930. t E. J. BLAKE ET AL 1,757,164

` BELT TENsIoNING DEVICE Filed sept.' 14, 192e 2 sheets-sheet l May 6*, 1930. A E. J.. BLAKE ET El. l 1,757,164

BELT TENsIoNING DEVICE lFiled sept. 14, 192e 2 sheets-sheet 2 III . vice that will be effective under all conditions Patented May 6, 1930 y UNITED STATES PATENT OFFICE-f i A ELI 2r. BLAKE, or BUFFALO, AND CLARENCE 1. LUsINK, OE ROCHESTER, NEW YORK,

ASSIGNORS, BY VIVIESNE ASSIGNMENTS, 'lO SIMPLEX EQUIPMENT COMPANY, INC.,

Y CE NEW YORK, N. Y., ACOREORATICN'O'E DELAWARE p r Y EELT-TENSIONING nEvICE Application led September`14, 192B. Serial No; 135,357. i

Our invention relates to generator. mountings and` drive mechanism` 1n car lighting equipmenty and, more especially, to belttightening devices for such generators.

An object of our invention 1s to provide a simple and effective device for insuring the desired tension of the belt'for axle drivenv generators. l

AAnother object of our invention is to provide a simple and rugged belt tightening de- Of weather. Y

A further object of our invention is to provide a belt tightening 'device that .may be readily assembled to the generator mounting and replaced without adjusting the spring tension.

A still further object of our invention is to provide a belt tension device whichin case of accident such as the breaking of thefbelt, will act as a buer against thefreeswing of a Generator and tend to'bring said genera:

tor tb rest without harm.

Anotherobject is .to provide a-deviceof the above-mentioned character that .is Vwell adapted to meet the varying Vconditions of hard practical use. Other objects will be in part obvious or in part pointed out hereinafter. f

The invention accordingly consists in the Vfeatures of construction, combinations of elements, and 'arrangements of parts as will be exemplified in the structure to-be hereinafter described and the .scope of the application of which will be indicated inthe following claims. *IT

In the accompanying drawings in which is shown one of various possible embodiments of our invention,-

Figure 1'is a vertical longitudinal view showing the spring tension device in section.

. Figure 2 is a horizontal plan view showing the spring housing and its connections.

Figure 3 is a vertical transverse viewshowing the open end of the spring housing and details of the generator suspension. c Figures 4 and 5 lare enlarged views of the closed end and open end, respectively, ofthe spring housing. l

` f Figure 6 1s a vertical transverse view show.-

ing an` alternative means for attaching the spring tension device. 1

Figure 7 is an enlarged view of the open end of the spring housing showing an alternative construction for retaining the spring and followers. f Y v Referring to the drawingsindetail, like parts being designated by like reference 'characters, and first considering the embodiment illustrated` in Figures 1 to 5, inclusive, a generator 1 is shown pivotally suspended by the arms .2` from a hinge pin 3 supported'by-the brackets L suitably secured to the car fram-V ing 5. yA belt tensioning device or'unit 6 is provided which at one end may be pivotally connected to vthe car fram-ing 5 through the bracket 7 and the pin 8; This device may Vcomprisea spring housing or barrel 9 provided at its closed end with lugs 10 to receive the pin 8. Within thehousing there may be assembled a compression spring 11 between two thrust collars 12 and 13 connected by the thrust bolt 14, rwhich may be provided at one end with a suitable head 15 and at the other with a threaded portion 16 to engage a correspondingly threaded portion 17 of a shackle 18.v The openy end of the housing 9 l maybe partially closed by the inward extensions from the annular cap 19, secured by the bolts 20. The shackle 18 may be provided with lugs' 21 co-engage, through the pin 22, a bracket 23 secured to one of the suspension arms 2 ofthe generator by the bolts and nuts 24 or other suitable means.

In `operating position, the generator is usually to the left of that shown in Figure 1 so that the tension of the belt'25, extending around the generator pulley 26 to operatively f connect the generator with a cooperating pulley on the caraxle (not shown), is normally determined by two factors, namely, the weight ofthe generator 1 and the thrust of the spring tension device 6 acting through its lever armwith respect to the hingepin 3. It will be noted that as the belt is shortened and the generator swings further to the left, from the position as shown in the drawings", the

spring A11 wouldbe further compressed under theaction of the bracket 2 3 acting through the pinj 22,A the shackle 1S and the Vthrust col- 'spring would be reduced,` its effective lever arnr increasedand'the elfective lever arm of the weight of the generator decreased so that by a proper proportioning of the related parts an approximately uniform tension or a desired variation of the tension of the belt may be obtained for any corresponding position ofthegenerator throughout the operating range of the spring tension device;

Should, for some cause, the belt break as frequently occurs when the belt runs up on the-flange of one of the pulleys, the generator would tend immediately to swing violently to the. rightunder the combined action of gravity and the thrust of the'spring. However, as soon as the compression spring V11 of the spring tension vdevice has expanded to the limit permitted by the thrust bolt l5, any further movement of the generatorfto the right would tend toY compress the spring and the action of the thrust bolt operating through the collar. l2 would act immediatelyto restrain the generator fromV furtherswinging to the right and quickly bring the generator toa neutral position corresponding to the maximum expansion. of the spring permitted by the thrust bolt and related parts; This feature of opposingmotion in eitheidirection 'from the neutral position, as indicated above, is of greatpractical advantage in .the art of car lighting. Railway cars are frequent-ly subjected to frequent violent jars and bumps, such as in coupling thecars-together or in starting a train, and certain features of our invention make it possible to prevent violent swinging :or oscillation ofthe generator, during such .jarring and bumping of thecars, and particularly when vthe ylatter takes place while a belt is broken. VIt permits the'construction of a spring tensiondevice or unit which may be equally well applied to either side of the generator.V Inl the ypreferred embodiment shown in the drawings,

. it is used as a compression memberv tending to'thrust the generator away from the Icar axle but it :may be equally well used on the side'away fromfthe axle 'as :atension member exerting. v a pull :on the generator throughout its usual operating, range, vproviding also the shock absorbing action as Y `described above of opposing the violent swinging 'of the'genf erato'r beyond the. neutralqposition such aswould be caused by breaking ofthe belt. Hitherto in car generator lmountings the action of the'spring devi-ce has been in one di` reetionf only` Aandino `bufferl has been providedl tol absorb this violent swinging of the gen-L erator which occurs when the belt breaks or spring mechanism in the barrel 9 with the open end practically closed bythe collar 13, protection from the weather is secured. By inclining the housing, as indicated in the drawings, any moisture which may collect Vtherein from Ycondensation or other causes will drain out of the open' end through the opening in the cap 19. This cap Vis so designed that cinders, ice or other obstructions will findno' lodgment within thebarrel.

In the preferred form of our invention a long stroke compression spring is used, preferably set-up to approximately three-fourths of its maximum compression so that there is little variationrin the spring thrust throughout its'working stroke. It will be noted that the spring tensiondevice constitutes a unit which, after it is assembled in the factory, requires no further adjustmentV and may be readily applied to the generator mounting by swinging thegenerator to the right from the position as shownin the drawing until the distance between theV pin 8 and the pin 22 corresponds to the distance between the holes in the lugs 10 and the holesV in the lugs 2l', thereby obviating'the labor of tightening the spring toits working distortion which is a necessary feature of the devices in general use, where the spring is assembled to the generator mounting in an unrestrained condition or at vfree length. By utilizing a unit construction' in which the spring is assembledv in the factory under great initial compression, this invention provides a highly efficient device using a minimum amount of material which requires arminimum amount of space 1 for its Vassembly and operation. Itis also to be noted that the'fact that no adjustment is required permits replacements to be made on the roadl without the necessity of highly skilled supervision.

Referring now to the embodiment of our invention illustrated in Figures 6 and 7, a modified form of connection between the belt tensioning device 6a andthe generator l is there illustratedV as well as a modified means for retaining the spring and follower vassembly' in the housing. In 'this embodiment, the shackle '18, instead of being connected to the pivotingfarin 2a ofthe generator, is' connected to `a supplemental' arm orv bracket 23 which extends substantially radially from the' Agenerator and isY preferably integral therewith. Inother respects, this construction may be identical with that j disclosed inV connection with. the first embodiment. They retaining ion Vment may be an annular plate 19 with inward projections or lips for preventing complete withdrawal ofthe assembled spring mechanism although, if desired,'said plate may be replaced by pinsl 20L extending transversely through apertures 19a in the end of the barrelA or housing 9a. Said pins 2Oa are preferably headed at one end and retained in assembled relation by means of cotters or the like 27. These pins 20a perform the same function as the tabs or inward projections on the annular cap 19 of the rst embodiment by extending as'chords across the open endjof the housing 9 for limiting outward movement of the springand follower assembly.

It is obvious that, if desired, these pins 20a may be used in connection with the first embodiment instead of the annular cap 19.

It`will thus be seen that there has 'been provided in this invention an apparatus in which the several objectshereinabove pointed out, together with many thoroughly practical advantages are successfully achieved and that the apparatus is well adapted to meet the varying conditions ofhard practical use.

As many possible embodiments may be made of the above invention and as many changes might be 4made in the embodiment above set fort-h, it is to be understood that all matter hereinbefore set forth or shown in the accompanying.drawings, is to be interpreted as illustrative and not in a limiting sense. i

Having now described our invention, we claim:

l. In combination with generator, a belt adapted .for driving the generator, means for pivotally suspending said generator and a spring Vfor tensioning said belt, said spring being adapted during a portion of its operating range to add tension to said belt and during another'portion of its operating range to restrict unduemo' tion of said generator."

2. In combination with a railway car, fa generator, a belt adapted for driving the generator, means for pivotally suspending said generator and a spring for tensioning said belt, said spring being also adapted to prevent harmful swinging of the generator in either direction.

3. In combination with a railway car, a generator, a belt adapted for driving the generator, means for pivotally suspending said generator and spring means for tensioning said belt, said spring means beingadapted to be applied either to one side or to the opposite side of said generator.

4. In combination with a railway car, a generator, a belt adapted for driving the generator, means for pivotally suspending said generator and spring means for tensioning Y said belt, said spring means being dible acta railway car,` a.

ing andeapable of'I pplication to one side or the .other ofsai'd generator.' i

5. 'In-.combination with a railwaycar, a

generator, a belt adapted for driving the geney erator, means for@ pivotally suspending said generator and' 'a spring ldevice for :tensioning said belt `andlpreventing. harmful swinging of said generator, said device beingV capable of applicationztojeitherside ofvsaid genera-tor.

' 6. 'In'combination with arail'way car, a generator, a belt adapted forv drivingthel gen.-

erator, j means for `pivotally suspending said generat'orandY a spring tensionl unit-'for ten,- sioning-said belt, saidlunit being under initial distortion and adaptedto be applied to said device,-withoutfurther adjustment, on either side'of said generator. f

'7. In combination with a; railway car, a `generator withan arm extending therefrom,

abelt adapted for drivingthe generator, ,c

means jfor pivotally suspending saidgener.-

ator, and spring means connected to said arm 1 Afortensioning ksaid belt, lsaid spring `means Ybeing capable of-application toleither'side of -saidgeneratoix`- '1 8i In combination witha railway car, a

generator with 'an arm' extendingtherefrom,

a 'belt adapted for Vdriving lthe generator, meansfforpivotally"suspending-,said generatrI andzaspring unit connected to said arm for tensioning said belt and preventing .harm fuls'wingingof the generator` in either direc tion, said spring unitvbeing Aadapted fork application to 'either sidevof 'said generator..

, 9L In carrlighting equipment,in` combinationv with, a: l. generator pivotally mounted beneath the carvand adapted Ato `be. driven by a -belt v from L the car axle, a`V belt .tensioning de- 'vice comprising a housing'a spring-'enclosed in said housing, and means connecting-said spring with said generator whereby swinging movement of said` generator ineither direciton with f respect Vto said :housing will cause further compresslon ofvsaid spring.

l 10: In-ear lighting equipment, in combination with a generator pivotally mountedbe'- neath the carandaflaptedto=.be driven by a beltf'f'romthe carl axle, a belt tensioning device comprising a housing, a spring mounted therein, thrust collars one at each end of said spring, anda thrust bolt for connecting 'said two collars, and means connecting said bolt Vwith said generator so that movement of said generator in either direction will canse furthericompression of said spring. 1

l1. In car lighting equipment, in combination with a generator pivotally mounted beneath the carand adapted'to be drive-11 by a belt from the car axle, a belt tensioning device comprising a housing, a compressed spring contained in said housing, a pair of movable thrust collars in said housing one at either end of said-spring, a bolt passing through one of said thrust collars and rigidly connected to the other of said thrust collars, ,-136

zmdmeams .vconne'etingsid last collar to said generator, sei'dboltjhaving an enlargement V.etl tlreend` thereof exterior of said rst thrust coller. v 5 12. in lightirg=eq1pment,n combina,-

tilona generator pivotally momted be. nea-th the @er am adaptedtobe driven by a bel-t fromthe ser axle, a; belt tensioning del vice Acomprising a.V spring',` mmmY connecting 1.0 sadsprngwith said generator 4so that movement of saidy generator .inf either direction will opposed'by seid spring', and a housing for enclosing said sprn .3

13. In car lightng'equ1pment,' in combina- 15 tion with su geneatorpivotaily mounted 'benth the our endadaptedlto loe driven by' a belttfrom the car axle, a spring tending to swing said generator may from said arde when said generator is' in Yrrorrxanl 'operating 20 .position and adaptee when. seid generator swings .out of? normal yoperzotirg position in a direction away from said car axle to tend to urgeseid' generator toward said car axle. 14. In our lighting equipment,i1r combination with a generator pivotally I'nount'efdf*beh nea-th thema' `end vaxwptsecll to be driver. by a said generator adapted to yf'eldinglyr'esist swinging 'movement' of s'suid gellelator an either dlrection fout' ef its; normul'operatig range. Y l v f 15. In' ein` l'ghting equipment, incombine tion', a; generator mountedfben'eeth lthercar to v swingtowrd and away fromm axle of the f :35 fait; ebelt for driving Salti 'gnerator' fiom seid"Y car'Y axle, e `compressi oni spring,S means connecting said spring .to tend to'- swing the generator in a irectiefn` away rOmtlfIe4v car axle .so als to telisol'r seid belt, ysaid y@ 'connecting means adapte to cause sx'cl` to oppose swinging movement of sidageerator in the opposite direction out 1 'of norrrialzopo-ating position when" the belt breaks;` Y f .455V In testimony whereof We aflxour sgnatures. Y .Y

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